MESSENGER
launched from Cape Canaveral Air Force Station, Fla., on Aug.
3, 2004, and will begin a yearlong orbital study of Mercury
in March 2011.

Though
the Sun is up to 11 times brighter at Mercury than we see on
Earth and surface temperatures can reach 450 degrees Celsius
(about 840 degrees Fahrenheit), MESSENGER's instruments will
operate at room temperature behind a sunshade of heat-resistant
ceramic fabric. The spacecraft will also pass only briefly over
the hottest parts of the surface, limiting exposure to heat reradiated
from the planet.